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DTSTART;TZID=Europe/Berlin:20231108T164500
DTEND;TZID=Europe/Berlin:20231108T180000
DTSTAMP:20260531T191633
CREATED:20231115T130147Z
LAST-MODIFIED:20231212T123220Z
UID:7004-1699461900-1699466400@crc326gaus.de
SUMMARY:Linear Relations of 1-Periods
DESCRIPTION:Frankfurter Seminar – Kolloquium des Instituts für Mathematik \nAnnette Huber-Klawitter (Universität Freiburg) \nAbstract: 1-Periods are complex numbers obtained by integrating an algebraic $1$-form defined over $\mathbf{Q}$ (e.g. $dx/x$) over a chain with algebraic end points. The set contains many interesting numbers (e.g.\, the values of $\log$ in algebraic numbers). Their transcendence and the relations between them are a classical question of transcendence theory. \nWe now have complete picture\, explaining the relations qualitatively in terms of obvious relations and also quantitatively\, by which we mean dimension formulas. \nIn the talk we are going to explain some of these general results and then discuss the application to the values of the hypergeometric function–recovering results of Wolfart. (joint work with G. Wüstholz)
URL:https://crc326gaus.de/event/linear-relations-of-1-periods/
LOCATION:Frankfurt\, Robert-Mayer-Str. 10\, Raum 711 groß
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231109T141500
DTEND;TZID=Europe/Berlin:20231109T151500
DTSTAMP:20260531T191633
CREATED:20230928T085309Z
LAST-MODIFIED:20231031T080227Z
UID:6279-1699539300-1699542900@crc326gaus.de
SUMMARY:Hodge Witt cohomology with modulus and duality
DESCRIPTION:Kay Rülling (Universität Wuppertal) \nAbstract: The theory of cube invariant modulus sheaves developed by Kahn-Miyazaki-Saito-Yamazaki allows to define for any sheaf with transfers and any smooth k-scheme X with effective Cartier divisor D a sheaf whose sections over X can be interpreted as regular sections on the complement of D with pole order at infinity bounded by D. This construction is functorial and has a certain universal property\, which makes it hard to compute explicitly. We apply it to the de Rham-Witt sheaves in positive characteristic p and show that in case the support of D has simple normal crossings these sheaves correspond under Grothendieck duality to de Rham Witt sheaves with zeros along D. From this we deduce refined versions of Ekedahl duality\, Poincaré duality for crystalline cohomology\, and Milne duality for motivic cohomology with p-primary torsion coefficients. This is joint work with Fei Ren. \nZoom Meeting-ID: 967 5163 9626 \nPasscode: last name of famous mathematician born in Königsberg (small letters)
URL:https://crc326gaus.de/event/tba-61/
LOCATION:Mainz\, Hilbertraum 05-432
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Georg Tamme":MAILTO:georg.tamme@uni-mainz.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231110T153000
DTEND;TZID=Europe/Berlin:20231110T170000
DTSTAMP:20260531T191633
CREATED:20231016T105750Z
LAST-MODIFIED:20231102T092256Z
UID:6688-1699630200-1699635600@crc326gaus.de
SUMMARY:Embedded normality in affine Grassmannians
DESCRIPTION:Seminar on Arithmetic Geometry \nJoão Lourenço (University of Münster) \nAbstract: Let k/F_p be an algebraically closed field and let G be any connected reductive group over a Laurent series field. To a given parahoric group model of G\, we can consider its affine Grassmannian which carry interesting parahoric orbit closures\, called Schubert varieties. It is known that these are always normal\, Cohen-Macaulay\, rational\, etc. for almost all G\, provided p is not torsion for G_der. The general strategy of proof goes back to Faltings\, but it is far from ideal\, as it relies on at least two constructions that cannot be done uniformly for all G. In this talk\, I’ll explain a new proof that circumvents this via two techniques: inversion of adjunction for splinters following Bhatt et al. (joint with Cass); and a Serre presentation for distributions of loop groups. \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-81/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231114T160000
DTEND;TZID=Europe/Berlin:20231114T170000
DTSTAMP:20260531T191633
CREATED:20231009T104327Z
LAST-MODIFIED:20231106T132454Z
UID:6405-1699977600-1699981200@crc326gaus.de
SUMMARY:Harris–Venkatesh plus Stark
DESCRIPTION:International Seminar on Automorphic Forms \nRobin Zhang (Massachusetts Institute of Technology) \nThe class number formula describes the behavior of the Dedekind zeta function at $s = 0$ and $s = 1$. The Stark and Gross conjectures extend the class number formula\, describing the behavior of Artin $L$-functions and $p$-adic $L$-functions at $s = 0$ and $s = 1$ in terms of units. The Harris–Venkatesh conjecture describes the residue of Stark units modulo $p$\, giving a modular analogue to the Stark and Gross conjectures while also serving as the first verifiable part of the broader conjectures of Venkatesh\, Prasanna\, and Galatius. In this talk\, I will draw an introductory picture\, formulate a unified conjecture combining Harris–Venkatesh and Stark for weight one modular forms\, and describe the proof of this in the imaginary dihedral case. \nhttps://tu-darmstadt.zoom.us/j/68048280736 \nThe password is the first Fourier coefficient of the modular j-function (as digits).
URL:https://crc326gaus.de/event/tba-64/
LOCATION:Zoom
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Claire Burrin":MAILTO:claire.burrin@math.uzh.ch
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231116T141500
DTEND;TZID=Europe/Berlin:20231116T151500
DTSTAMP:20260531T191633
CREATED:20231012T085727Z
LAST-MODIFIED:20231108T085912Z
UID:6648-1700144100-1700147700@crc326gaus.de
SUMMARY:Bordism of commuting involutions
DESCRIPTION:Markus Hausmann (Bonn) \nAbstract: The bordism ring of manifolds equipped with an involution was computed additively by Conner-Floyd (1965) and multiplicatively by Alexander (1972). Alexander’s description is explicit but complicated and doesn’t seem to enjoy a simple algebraic interpretation.\nIn this talk I will discuss that if one extends the problem and\n1) considers the collection of bordism rings of manifolds with n commuting involutions for all n\, and\n2) takes into account the representation sphere-grading\,\nthen there is a simple algebraic universal property. \nThis is joint work with Stefan Schwede. \nZoom Meeting-ID: 967 5163 9626 \nPasscode: last name of famous mathematician born in Königsberg (small letters)
URL:https://crc326gaus.de/event/tba-76/
LOCATION:Mainz\, Hilbertraum 05-432
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231117T133000
DTEND;TZID=Europe/Berlin:20231117T150000
DTSTAMP:20260531T191633
CREATED:20231103T134345Z
LAST-MODIFIED:20231103T134345Z
UID:6906-1700227800-1700233200@crc326gaus.de
SUMMARY:Drinfeld modular forms of arbitrary rank and their partial derivatives
DESCRIPTION:Oğuz Gezmiş (Universität Heidelberg) \nIn the 1980s\, David Goss introduced Drinfeld modular forms in the rank two case where the analogy with the setting of elliptic modular forms was quite striking. Recently\, using the work of Häberli and Pink\, Basson\, Breuer\, and Pink successfully generalized the theory of Drinfeld modular forms to the arbitrary rank setting and provided explicit examples. In this talk\, we describe several identities on the derivatives of Drinfeld modular forms of higher rank and introduce a differential operator acting on the space of such forms. Moreover\, we construct a finitely generated algebra containing all the Drinfeld modular forms for the full modular group and discuss its stability under partial derivatives as well as the transcendence of its generators at CM points. This is a joint work with Yen-Tsung Chen. \n 
URL:https://crc326gaus.de/event/drinfeld-modular-forms-of-arbitrary-rank-and-their-partial-derivatives/
LOCATION:Heidelberg\, Mathematikon\, SR A and Livestream
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231117T153000
DTEND;TZID=Europe/Berlin:20231117T170000
DTSTAMP:20260531T191633
CREATED:20231016T105925Z
LAST-MODIFIED:20231106T131959Z
UID:6690-1700235000-1700240400@crc326gaus.de
SUMMARY:Factorization central extensions of the loop group
DESCRIPTION:Seminar on Arithmetic Geometry \nYifei Zhao (University of Münster) \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-82/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231121T160000
DTEND;TZID=Europe/Berlin:20231121T170000
DTSTAMP:20260531T191633
CREATED:20231009T104539Z
LAST-MODIFIED:20231113T102401Z
UID:6407-1700582400-1700586000@crc326gaus.de
SUMMARY:Around the Gauss circle problem
DESCRIPTION:International Seminar on Automorphic Forms \nSteve Lester (King’s College London) \nHardy conjectured that the error term arising from approximating the number of lattice points lying in a radius-R disc by its area is O(R^{1/2+o(1)}). One source of support for this conjecture is a folklore heuristic that uses i.i.d. random variables to model the lattice points lying near the boundary and square-root cancellation of sums of these random variables. In this talk I will examine this heuristic and discuss how lattice points near the circle interact with one another. This is joint work with Igor Wigman. \nhttps://tu-darmstadt.zoom.us/j/68048280736 \nThe password is the first Fourier coefficient of the modular j-function (as digits).
URL:https://crc326gaus.de/event/tba-65/
LOCATION:Zoom
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Claire Burrin":MAILTO:claire.burrin@math.uzh.ch
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231123T141500
DTEND;TZID=Europe/Berlin:20231123T151500
DTSTAMP:20260531T191633
CREATED:20231012T085916Z
LAST-MODIFIED:20231113T130726Z
UID:6650-1700748900-1700752500@crc326gaus.de
SUMMARY:Combing a hedgehog over a field
DESCRIPTION:Alexey Ananyevskiy (LMU München) \nA classical result in differential topology says that there are no nowhere vanishing vector fields on a 2-sphere. One may ask a similar question in algebraic geometry: does the tangent bundle to a sphere given by the equation x^2+y^2+z^2=1 over some field k have a nowhere vanishing section? Or more generally\, when does the tangent bundle on an affine quadratic q=1 with q being a homogeneous degree 2 polynomial have a nowhere vanishing section? We give an essentially full answer to this question assuming that the quadric q=1 has a rational point. In particular\, the 2-sphere x^2+y^2+z^2=1 over a field k has a nowhere vanishing vector field if and only if -1 is a sum of 4 squares in k. The proof uses a mixture of results from the motivic homotopy theory\, Chow-Witt rings and some constructions from the theory of quadratic forms.\nThis is a joint work with Marc Levine. \nZoom Meeting-ID: 967 5163 9626 \nPasscode: last name of famous mathematician born in Königsberg (small letters)
URL:https://crc326gaus.de/event/tba-77/
LOCATION:Mainz\, Hilbertraum 05-432
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231124T153000
DTEND;TZID=Europe/Berlin:20231124T170000
DTSTAMP:20260531T191633
CREATED:20231016T110102Z
LAST-MODIFIED:20231115T094550Z
UID:6692-1700839800-1700845200@crc326gaus.de
SUMMARY:The quadratic Euler characteristic of a smooth projective same-degree complete intersection
DESCRIPTION:Seminar on Arithmetic Geometry \nAnneloes Viergever (University of Duisburg-Essen) \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-83/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231128T160000
DTEND;TZID=Europe/Berlin:20231128T170000
DTSTAMP:20260531T191633
CREATED:20231009T104721Z
LAST-MODIFIED:20231123T081516Z
UID:6409-1701187200-1701190800@crc326gaus.de
SUMMARY:Restricted Arithmetic Quantum Unique Ergodicity
DESCRIPTION:International Seminar on Automorphic Forms \nThe quantum unique ergodicity conjecture of Rudnick and Sarnak concerns the mass equidistribution in the large eigenvalue limit of Laplacian eigenfunctions on negatively curved manifolds. This conjecture has been resolved by Lindenstrauss when this manifold is the modular surface assuming these eigenfunctions are additionally Hecke eigenfunctions\, namely Hecke-Maass cusp forms. I will discuss a variant of this problem in this arithmetic setting concerning the mass equidistribution of Hecke-Maass cusp forms on submanifolds of the modular surface. \nPeter Humphries (University of Virginia) \nhttps://tu-darmstadt.zoom.us/j/68048280736 \nThe password is the first Fourier coefficient of the modular j-function (as digits).
URL:https://crc326gaus.de/event/tba-66/
LOCATION:Zoom
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Claire Burrin":MAILTO:claire.burrin@math.uzh.ch
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231201T133000
DTEND;TZID=Europe/Berlin:20231201T150000
DTSTAMP:20260531T191633
CREATED:20231117T115653Z
LAST-MODIFIED:20231124T131815Z
UID:7042-1701437400-1701442800@crc326gaus.de
SUMMARY:A "Galois" categorical p-adic local Langlands for GL(2\,Qp)
DESCRIPTION:Christian Johansson (Universität Göteborg) \nI will introduce the p-adic local Langlands correspondence for GL(2\,Qp)\, in the forms established by Colmez and Paskunas\, and then give an interpretation of it as an embedding of categories (a form of “localization”). Time permitting\, I will also discuss local-global formulas for singular cohomology of modular curves that you can get from this framework. This is joint work with James Newton and Carl Wang-Erickson.
URL:https://crc326gaus.de/event/tba-60/
LOCATION:Heidelberg\, Mathematikon\, SR A and Livestream
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231201T153000
DTEND;TZID=Europe/Berlin:20231201T170000
DTSTAMP:20260531T191633
CREATED:20231016T110225Z
LAST-MODIFIED:20231121T073143Z
UID:6694-1701444600-1701450000@crc326gaus.de
SUMMARY:Wonderful compactification over an arbitrary base scheme
DESCRIPTION:Seminar on Arithmetic Geometry \nWonderful compactifications of adjoint reductive groups over an algebraically closed field play an important role in algebraic geometry and representation theory. In this talk\, we will construct an equivariant compactification for adjoint reductive groups over arbitrary base schemes\, which parameterize classical wonderful compactifications of De Concini and Procesi as geometric fibers. Our construction is based on a variant of the Artin–Weil method of birational group laws. In particular\, our construction gives a new intrinsic construction of wonderful compactifications. If time permits\, we will also discuss several applications of our compactification in the study of torsors under reductive group schemes. \nShang Li (Paris-Saclay University) \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-84/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231205T153000
DTEND;TZID=Europe/Berlin:20231205T170000
DTSTAMP:20260531T191633
CREATED:20231016T110452Z
LAST-MODIFIED:20231128T125246Z
UID:6696-1701790200-1701795600@crc326gaus.de
SUMMARY:Theta functions for the projective plane relative a smooth cubic
DESCRIPTION:Seminar on Arithmetic Geometry \nHelge Ruddat (University of Stavanger) \nGross-Hacking-Siebert generalized the classical Jacobi theta function from abelian varieties to more general log Calabi-Yau manifolds. Landau-Ginzburg superpotentials in mathematical physics give particular examples of such theta functions. Zaslow\, Gräfnitz and I compute the Landau-Ginzburg superpotential of the mirror symmetry dual of P^2 relative a smooth elliptic curve. This infinite power series is tropically defined and can be identified with a generating function for 2-contact point rational Gromov-Witten invariants of (X\,E). We found that this series also equals the open mirror map for outer Aganagic-Vafa branes in the canonical bundle K_X\, so it is closely related to a solution to a Lerche-Mayr system of two differential equations and it is also a generating function of holomorphic disk counts. The fundamental structure used to study theta functions is the wall structure. I am going to explain the background and usefulness of this recent technology. \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-85/
LOCATION:Darmstadt\, Room 244 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231205T160000
DTEND;TZID=Europe/Berlin:20231205T170000
DTSTAMP:20260531T191633
CREATED:20231009T104848Z
LAST-MODIFIED:20231128T105630Z
UID:6411-1701792000-1701795600@crc326gaus.de
SUMMARY:Murmurations of holomorphic modular forms in the weight aspect
DESCRIPTION:International Seminar on Automorphic Forms \nMin Lee (University of Bristol) \nIn April 2022\, He\, Lee\, Oliver\, and Pozdnyakov made an interesting discovery using machine learning – a surprising correlation between the root numbers of elliptic curves and the coefficients of their L-functions. They coined this correlation ‘murmurations of elliptic curves.’ Naturally\, one might wonder whether we can identify a common thread of ‘murmurations’ in other families of L-functions. In this talk\, I will introduce a joint work with Jonathan Bober\, Andrew R. Booker and David Lowry-Duda\, demonstrating murmurations in holomorphic modular forms. \nhttps://tu-darmstadt.zoom.us/j/68048280736 \nThe password is the first Fourier coefficient of the modular j-function (as digits).
URL:https://crc326gaus.de/event/tba-67/
LOCATION:Zoom
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Claire Burrin":MAILTO:claire.burrin@math.uzh.ch
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231206T160000
DTEND;TZID=Europe/Berlin:20231206T170000
DTSTAMP:20260531T191633
CREATED:20231120T080333Z
LAST-MODIFIED:20231127T102533Z
UID:7047-1701878400-1701882000@crc326gaus.de
SUMMARY:Global Smoothings of Toroidal Crossing Varieties
DESCRIPTION:Oberseminar Algebra und Geometrie \nHelge Ruddat (University of Stavanger) \nAs a natural generalization of normal crossing singularities\, I am going to define toroidal crossing singularities and toroidal crossing varieties and explain how to produce them in large quantities by subdividing lattice polytopes. I will then explain the statement of a global smoothing theorem proved jointly with Felten and Filip. The theorem follows the tradition of well-known theorems by Friedman\, Kawamata-Namikawa and Gross-Siebert. In order to apply a variant of the theorem to construct (conjecturally all) projective Fano manifolds with non-empty anticanonical divisor\, Corti and Petracci discovered the necessity to allow for particular singular log structures that are known by the inspiring name “admissible”‘. I will explain the beautiful classical geometric curve-in-surface geometry that underlies this notion and hint at why we believe that we can feed these singular log structures into the smoothing theorem in order to produce all 98 Fano threefolds with very ample anticanonical class by a single method.
URL:https://crc326gaus.de/event/tba-94/
LOCATION:Frankfurt\, Robert-Mayer-Str. 10\, Raum 711 groß
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231212T160000
DTEND;TZID=Europe/Berlin:20231212T170000
DTSTAMP:20260531T191633
CREATED:20231009T105043Z
LAST-MODIFIED:20231204T084236Z
UID:6413-1702396800-1702400400@crc326gaus.de
SUMMARY:Resonances of Schottky surfaces
DESCRIPTION:International Seminar on Automorphic Forms \nAnke Pohl (University of Bremen) \nThe investigation of L^2-Laplace eigenvalues and eigenfunctions for hyperbolic surfaces of finite area is a classical and exciting topic at the intersection of number theory\, harmonic analysis and mathematical physics. In stark contrast\, for (geometrically finite) hyperbolic surfaces of infinite area\, the discrete L^2-spectrum is finite. A natural replacement are the resonances of the considered hyperbolic surface\, which are the poles of the meromorphically continued resolvent of the Laplacian. \nThese spectral entities also play an important role in number theory and various other fields\, and many fascinating results about them have already been found; the generalization of Selberg’s 3/16-theorem by Bourgain\, Gamburd and Sarnak is a well-known example. However\, an enormous amount of the properties of such resonances\, also some very elementary ones\, is still undiscovered. A few years ago\, by means of numerical experiments\, Borthwick noticed for some classes of Schottky surfaces (hyperbolic surfaces of infinite area without cusps and conical singularities) that their sets of resonances exhibit unexcepted and nice patterns\, which are not yet fully understood. \nAfter a brief survey of some parts of this field\, we will discuss an alternative numerical method\, combining tools from dynamics\, zeta functions\, transfer operators and thermodynamic formalism\, functional analysis and approximation theory. The emphasis of the presentation will be on motivation\, heuristics and pictures. This is joint work with Oscar Bandtlow\, Torben Schick and Alex Weisse. \nhttps://tu-darmstadt.zoom.us/j/68048280736 \nThe password is the first Fourier coefficient of the modular j-function (as digits).
URL:https://crc326gaus.de/event/tba-68/
LOCATION:Zoom
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Claire Burrin":MAILTO:claire.burrin@math.uzh.ch
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231214T141500
DTEND;TZID=Europe/Berlin:20231214T151500
DTSTAMP:20260531T191633
CREATED:20231012T090245Z
LAST-MODIFIED:20231207T075847Z
UID:6652-1702563300-1702566900@crc326gaus.de
SUMMARY:Quadratic Atiyah-Bott Localisation
DESCRIPTION:Alessandro d’Angelo (Stockholm) \nAbstract: The Atiyah-Bott localisation theorem and the Graber-Pandharipande virtual localisation formula are standard tools for studying enumerative problems in the presence of a torus action. M. Levine proved similar results for Witt sheaf cohomology\, allowing us to retain quadratic information about the enumerative count. We will show how to extend the Atiyah-Bott localisation theorem to any SL-oriented motivic spectrum\, once the algebraic Hopf map is inverted. As an application\, we will also provide the appropriate virtual localisation formula for fundamental classes in this context. \nZoom Meeting-ID: 967 5163 9626 \nPasscode: last name of famous mathematician born in Königsberg (small letters)
URL:https://crc326gaus.de/event/tba-78/
LOCATION:Mainz\, Hilbertraum 05-432
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231214T143000
DTEND;TZID=Europe/Berlin:20231214T153000
DTSTAMP:20260531T191633
CREATED:20231107T120412Z
LAST-MODIFIED:20231204T112155Z
UID:6926-1702564200-1702567800@crc326gaus.de
SUMMARY:Stationary Descendents and the Discriminant Modular Form
DESCRIPTION:TGiF-Seminar: Tropical geometry in Frankfurt (First meeting Winter Semester 2023/24) \nAdam Afandi (Universität Münster) \nAbstract: By using the Gromov-Witten/Hurwitz correspondence\, Okounkov and Pandharipande showed that certain generating functions of stationary descendent Gromov-Witten invariants of a smooth elliptic curve are quasimodular forms. In this talk\, I will discuss the various ways one can express the discriminant modular form in terms of these generating functions. The motivation behind this calculation is to provide a new perspective on tackling a longstanding conjecture of Lehmer from the middle of the 20th century; Lehmer posited that the Ramanujan tau function (i.e. the Fourier coefficients of the discriminant modular form) never vanishes. The connection with Gromov-Witten invariants allows one to translate Lehmer’s conjecture into a combinatorial problem involving characters of the symmetric group and shifted symmetric functions.
URL:https://crc326gaus.de/event/tba-92/
LOCATION:Frankfurt\, Robert-Mayer-Str. 10\, Raum 711 groß
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231214T160000
DTEND;TZID=Europe/Berlin:20231214T170000
DTSTAMP:20260531T191633
CREATED:20231107T121051Z
LAST-MODIFIED:20231204T112026Z
UID:6928-1702569600-1702573200@crc326gaus.de
SUMMARY:Refined tropical curve counting with descendants
DESCRIPTION:TGiF-Seminar: Tropical geometry in Frankfurt (First meeting Winter Semester 2023/24) \nAjith Urundolil-Kumaran (University of Cambridge) \nAbstract: We introduce the enumerative geometry of curves in the algebraic torus (C*)^2. We show that a certain class of invariants associated with moduli spaces of curves in (C*)^2 can be calculated explicitly using a refined tropical correspondence theorem. If time permits we will explain how the proof relies on higher double ramification cycles and work of Buryak-Rossi on integrable systems on the moduli space of curves. This is joint work with Patrick Kennedy-Hunt and Qaasim Shafi. \n 
URL:https://crc326gaus.de/event/tba-93/
LOCATION:Frankfurt\, Robert-Mayer-Str. 10\, Raum 711 groß
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231215T133000
DTEND;TZID=Europe/Berlin:20231215T150000
DTSTAMP:20260531T191633
CREATED:20231206T105109Z
LAST-MODIFIED:20231206T105410Z
UID:7399-1702647000-1702652400@crc326gaus.de
SUMMARY:Torsion in Griffiths Groups
DESCRIPTION:Theodosis Alexandrou (Universität Hannover) \nThe Griffiths group $Griff^{i}(X)$ of a smooth complex projective variety $X$ is the group of nullhomologous codimension$-i$ cycles on $X$ modulo algebraic equivalence. Recently Schreieder gave the first examples of smooth complex projective varieties $X$ for which the Griffiths group has infinite torsion. In his examples the infinitely many torsion classes are of order 2. In this talk we show that for any integer $n\geq 2$\, there is a smooth complex projective $5-$fold $X$ whose third Griffiths group contains infinitely many torsion elements of order $n$.
URL:https://crc326gaus.de/event/torsion-in-griffiths-groups/
LOCATION:Heidelberg\, Mathematikon\, SR A and Livestream
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231215T153000
DTEND;TZID=Europe/Berlin:20231215T170000
DTSTAMP:20260531T191633
CREATED:20231016T110711Z
LAST-MODIFIED:20231205T130426Z
UID:6698-1702654200-1702659600@crc326gaus.de
SUMMARY:Motivic Linking
DESCRIPTION:Seminar on Arithmetic Geometry \nClémentine Lemarié—Rieusset (University of Burgundy) \nIn this talk I will present motivic linking\, a new application in algebraic geometry of motivic homotopy theory (specifically\, of quadratic intersection theory). Over a perfect field F\, motivic linking consists in the study of how two (nice) closed F-subschemes of a (nice) ambient F-scheme are linked (i.e. intertwined) and is a counterpart to linking in knot theory. More specifically\, I will present counterparts in algebraic geometry to the linking number of two oriented disjoint knots (the number of times one of the knots turns around the other knot). For the most part\, these counterparts take values in the Witt group of F or in the Grothendieck-Witt group of F\, rather than in the group of integers. There will be several examples\, including closed immersions between smooth models of motivic spheres and closed immersions between projective spaces. \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-86/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20231222T153000
DTEND;TZID=Europe/Berlin:20231222T170000
DTSTAMP:20260531T191633
CREATED:20231016T110911Z
LAST-MODIFIED:20231215T072743Z
UID:6700-1703259000-1703264400@crc326gaus.de
SUMMARY:Deformations of $(G\,\mu)$-Displays
DESCRIPTION:Seminar on Arithmetic Geometry \nMohammad Hadi Hedayatzadeh (Institute for Research in Fundamental Sciences) \nIn this talk\, I will discuss a joint project with A. Partofard\, on prismatic displays with additional structures. I will start with a concise overview of the theory of displays developed by Th. Zink\, which serves as a generalization of Dieudonné theory. Displays play a crucial role in the study of Barsotti-Tate groups when the base is not a perfect field of positive characteristic. Zink has further expanded the theory by introducing windows over frames. In another direction\, in order to construct integral models of certain Shimura varieties that are not of Abelian type\, O. Bültel defined and studied displays with additional structures called $(G\,\mu)$-displays. \nIn this joint project with Partofard\, we define and study the stack of prismatic $(G\,\mu)$-displays over the quasi-syntomic site\, which is better adapted to the setting of pefectoid geometry and is closely related to the stack of $G$-torsors over the Fargues-Fontaine curve and local Shimura varieties. When $G$ is the general linear group\, our stack is the same as the stack of admissible prismatic $F$-crystals developed by Anschütz-LeBras\, which is equivalent to the stack of $p$-divisible groups. We also prove a Grothendieck-Messing style deformation result for these prismatic displays\, which\, for the general linear group\, answers a question of Anschütz-LeBras. \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-87/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240112T133000
DTEND;TZID=Europe/Berlin:20240112T150000
DTSTAMP:20260531T191633
CREATED:20240101T193202Z
LAST-MODIFIED:20240101T193202Z
UID:7526-1705066200-1705071600@crc326gaus.de
SUMMARY:Equivariant motives and actions of finite reductive groups
DESCRIPTION:Can Yaylali (Darmstadt/Paris) \nAbstract: A finite reductive group G^F is defined as the fixed points of a reductive group G/F_q under the q-Frobenius endomorphism. Their representations were studied by Deligne-Lusztig and Brokemper gave a description of the G^F-equivariant intersection ring of a point (the ring classifying G^F-invariant cycles). Focusing on the latter\, I will give an introduction to (rational) motives with group actions and how this is related to equivariant intersection theory. I will use this formalism to relate motives with G^F-action to equivariant motives on the associated flag variety. I will also explain how this relates to Brokemper’s computations on algebraic cycles. If time permits\, I will try to discuss the implications on l-adic cohomology and how this can be used in the future to study motivic representation theory of G^F following Deligne-Lusztig.
URL:https://crc326gaus.de/event/equivariant-motives-and-actions-of-finite-reductive-groups/
LOCATION:Heidelberg\, Mathematikon\, SR A and Livestream
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Christian Dahlhausen":MAILTO:cdahlhausen@mathi.uni-heidelberg.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240116T160000
DTEND;TZID=Europe/Berlin:20240116T170000
DTSTAMP:20260531T191633
CREATED:20231009T105238Z
LAST-MODIFIED:20231221T093008Z
UID:6415-1705420800-1705424400@crc326gaus.de
SUMMARY:Automorphism group of Cartan modular curves
DESCRIPTION:International Seminar on Automorphic Forms \nPietro Mercuri (University of Rome – La Sapienza) \nWe consider the modular curves associated to a Cartan subgroup of GL(2\,Z/nZ) or to a particular class of subgroups of GL(2\,Z/nZ) containing the Cartan subgroup as a normal subgroup. We describe the automorphism group of these curves when the level is large enough. If time permits\, we give a sketch of the proof. \nhttps://tu-darmstadt.zoom.us/j/68048280736 \nThe password is the first Fourier coefficient of the modular j-function (as digits).
URL:https://crc326gaus.de/event/tba-69/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Claire Burrin":MAILTO:claire.burrin@math.uzh.ch
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240119T140000
DTEND;TZID=Europe/Berlin:20240119T180000
DTSTAMP:20260531T191633
CREATED:20231123T090322Z
LAST-MODIFIED:20231123T090429Z
UID:7232-1705672800-1705687200@crc326gaus.de
SUMMARY:Conformal Field Theory
DESCRIPTION:14:00-15:00: Britta Spät (University of Wuppertal): On the McKay Conjecture \n15:15-16:15: Ida Zadeh (Johannes Gutenberg University Mainz): Mathieu Moonshine and T4/Z3 sigma-models \n17:00-18:00: David Reutter (University of Hamburg): A braided tensor 2-category from link homology
URL:https://crc326gaus.de/event/conformal-field-theory/
LOCATION:Darmstadt\, Room S214/24
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240119T153000
DTEND;TZID=Europe/Berlin:20240119T170000
DTSTAMP:20260531T191633
CREATED:20231016T111231Z
LAST-MODIFIED:20240112T073106Z
UID:6704-1705678200-1705683600@crc326gaus.de
SUMMARY:Enumerating motivic nearby cycles
DESCRIPTION:Seminar on Arithmetic Geometry \nRan Azouri (Sorbonne Paris North University) \nA^1 homotopy theory provides tools to refine geometric invariants on integers to quadratic forms. A key such invariant is the quadratic Euler characteristic; Ayoub’s motivic nearby cycles provide a tool to study singularities in the world of A^1 homotopy.\nIn the talk I will explain how to compute the quadratic Euler characteristic on the motivic nearby cycles spectrum around certain singularities\, using an explicit semistable reduction construction. This\, together with a work of Levine\, Pepin Lehalleur and Srinivas\, adds up to a quadratic conductor formula on schemes with semi-quasihomogeneous singularities\, refining formulas of Milnor and Deligne.\nLater I will describe how\, in a work in progress with Emil Jacobsen\, we use a similar semistable reduction argument to compute the motivic monodromy on nearby cycles\, generalising to motives the Picard-Lefschetz formula of Deligne and Katz. \nZoom (635 7328 0984\, Password: smallest six digit prime).
URL:https://crc326gaus.de/event/tba-89/
LOCATION:Darmstadt\, Room 401 and Zoom\, Schlossgartenstraße 7\, Darmstadt\, 64289\, Germany
CATEGORIES:GAUS-Seminar
ORGANIZER;CN="Sabrina Pauli":MAILTO:pauli@mathematik.tu-darmstadt.de
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240123T090000
DTEND;TZID=Europe/Berlin:20240123T100000
DTSTAMP:20260531T191633
CREATED:20231009T105405Z
LAST-MODIFIED:20240109T101527Z
UID:6417-1706000400-1706004000@crc326gaus.de
SUMMARY:The BZSV duality and the relative Langlands program
DESCRIPTION:International Seminar on Automorphic Forms \nWee Teck Gan (National University of Singapore) \nI will discuss a duality of Hamiltonian group varieties proposed in a recent preprint of Ben-Zvi\, Sakellaridis and Venkatesh\, which gives a new paradigm for the relative Langlands program.\nI will then discuss a joint work with Bryan Wang on instances of this duality for certain Hamiltonian varieties which quantize to generalized Whittaker models. \nYou can join the Zoom meeting at https://tu-darmstadt.zoom.us/j/68048280736 \nThe password is the first Fourier coefficient of the modular j-function (as digits).
URL:https://crc326gaus.de/event/tba-70/
LOCATION:Zoom
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240123T140000
DTEND;TZID=Europe/Berlin:20240123T150000
DTSTAMP:20260531T191633
CREATED:20231220T150741Z
LAST-MODIFIED:20231220T151059Z
UID:7510-1706018400-1706022000@crc326gaus.de
SUMMARY:Étale cohomology of the moduli stack of rank 2 vector bundles on the Fargues-Fontaine curve
DESCRIPTION:Seminar: Non-archimedean geometry \nRuth Wild (Universität Bonn) \nAbstract: Motivated by classical calculations\, we consider the problem of calculating the etale cohomology of the moduli stack Bun<sub>2</sub> of rank 2 vector bundles on the Fargues-Fontaine curve\, as introduced by Fargues and Scholze in their geometrization of the Local Langlands correspondence. We achive this by analyzing a stratafication of this stack and the simple cohomological behavior of the different strata. Along the way\, we prove the description of the dualizing sheaf on Bun<sub>2</sub>.
URL:https://crc326gaus.de/event/etale-cohomology-of-the-moduli-stack-of-rank-2-vector-bundles-on-the-fargues-fontaine-curve/
LOCATION:Frankfurt\, Rober-Mayer-Str. 10\, Raum 711 klein
CATEGORIES:GAUS-Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20240125T170000
DTEND;TZID=Europe/Berlin:20240125T180000
DTSTAMP:20260531T191633
CREATED:20231012T090458Z
LAST-MODIFIED:20240514T072156Z
UID:6654-1706202000-1706205600@crc326gaus.de
SUMMARY:CRC-Colloquium
DESCRIPTION:15:30 Uhr Ben Heuer (Universität Frankfurt): p-adic non-abelian Hodge theory for non-p-adic mathematicians\n16:30 Coffee and Cake\n17:00 Uhr Jan Bruinier (TU Darmstadt): Theta functions in geometry and arithmetic\n18:30 Uhr: Dinner \nAbstract B. Heuer:\nIn p-adic non-abelian Hodge theory\, we study p-adic representations of fundamental groups of projective varieties. This talk will give an introduction to this subject without assuming any background in p-adic geometry. Based on examples\, I will explain the “p-adic Simpson correspondence”\, with an emphasis on the relation to complex geometry. I will discuss recent advances\, the main open questions in the area\, and potential applications to complex geometry. \nAbstract J. Brunier:\nWe explain how theta functions can be used to study positive definite quadratic forms and their representation numbers. For indefinite quadratic forms\, Kudla and Millson showed that there are analogous theta functions relating the geometry of special cycles on locally symmetric spaces to modular forms. Conjectures of Kudla predict similar results for arithmetic special cycles in Arakelov Chow groups on integral models of orthogonal Shimura varieties. We will also report on some recent results in this context. \nZoom Meeting-ID: 967 5163 9626 \nPasscode: last name of famous mathematician born in Königsberg (small letters)
URL:https://crc326gaus.de/event/tba-79/
LOCATION:Mainz\, Raum 05-426
CATEGORIES:GAUS-Seminar
END:VEVENT
END:VCALENDAR